The present invention relates to explosive detonators, and more particularly, relates to explosive detonators wherein the primer charge is protected and the output of the primer charge is focused toward the base charge providing efficient initiation.
There are various detonator designs known in the art which basically fall into three categories. The first category of detonators are constructed such that the primer charge is located on top of the base charge and in intimate contact with the delay element. These designs do not provide for protection of the primer charge against sympathetic detonation, nor do those designs provide for focusing of the output from the primer charge for efficient detonation.
A second category of detonators known in the art are constructed such that the primer charge is protected in some manner, but includes a gap between the primer charge and the delay element, and thus, reliable initiation is not obtained. Further, these designs do not provide a means to focus the primer charge output toward the base charge and thus, are inefficient.
The third category of detonators known in the art are common among European manufacturers and are constructed such that the primer charge is located inside the delay element which is in intimate contact with the delay element core and protected against sympathetic detonation, but these designs do not focus the primer charge output toward the base charge and thus, are also inefficient.
None of the known detonator designs provide (1) primer charge protection against sympathetic initiation, (2) focusing of the primer charge output for efficient base charge initiation, and (3) intimate contact between the delay element and the primer charge for reliable initiation. The present invention provides a detonator which supplies protection of the primer charge, reliable initiation and efficient use of the primer charge and base charge materials.